Switch devices are already known for opening and closing an electrical line in which a blade-shaped contact piece is supported by a drive member that is movable in translation between a position in which said contact piece presses against two contact terminals, thereby closing the electrical line, and a position in which it is spaced apart from said contact terminals, thereby opening the electrical line.
During such movements in translation, the contact piece is guided by rods along which it slides so as to ensure that said contact piece is properly applied against the contact terminals.
Nevertheless, such guidance presents the drawback that the friction which acts between the contact piece and the guide rods generates dust which can become deposited on the electrical contact surfaces and, in the long run, can degrade the reliability of the switch device.
European patent EP 0 670 579 attempts to solve that problem by a switch device comprising a drive member having an axially displaceable contact piece and two parallel flexible blades each presenting a central portion secured to the drive member and two ends each received in a cradle of a stationary support.
That switch device is satisfactory insofar as friction is eliminated with respect to the drive member.
European patent application EP 1 047 089 discloses a coaxial relay having moving blades for opening and closing coaxial contacts. Each of the blades is carried by an actuator fixed at its top end to a return member. The return member has a central branch on which the actuator is fixed, and on either side thereof two lateral branches serving, with the help of screws, to fix the return member to a wall of the relay. Because of the presence of multiple branches, that return member is relatively bulky and cannot be adapted to use in devices of small dimensions.
U.S. Pat. No. 5,471,183 discloses a coaxial switch having connection elements each carried by a dielectric support. The dielectric support is fixed to two superposed return members and is secured to a permanent magnet suitable for co-operating with another magnet carried by a rotor for actuating the corresponding dielectric support. That switch has no actuator coming into contact with the dielectric support in order to move it. In addition, because the dielectric support is fixed to the two blades, that support presents height that is relatively large, thereby making the switch more bulky.
There exists a need to further improve switch devices, in particular by reducing the number of component parts and by reducing the sizes thereof.
There also exists a need not only to eliminate friction with respect to the drive member, but also friction with respect to an actuator for driving the drive member.
There also exists a need to be able to act simultaneously on a plurality of switches.